The patron saint of Castano Primo is Saint Zeno, celebrated on the last Sunday of October.
The Feast of the Holy Crucifix, the most deeply felt religious event in the whole area, has been held every 25 years since the mid-19th century and draws thousands of people from the town, nearby villages and the whole province; the crucifix's current appearance dates from a 1759 restoration. The town also holds the Church of the Madonna dei Poveri and the small Church of San Bernardo alla Malpaga.
